Is zombie mode that powerful? is there another mode out there that takes care of the DAG sitatuon?
https://www.reddit.com/r/gpumining/comments/lwh3un/4gb_fury_radeon_pro_duo_25mhs_per_cardmore_if_i/I played with this myself and did some fun stuff.
The Radeon Pro Duo, which is 2x Fury 4GB card in one with a X99 Board and 6850X(lots of PCI-E lanes). It's possible to have these Dual GPUs still do 25-27mh/s on ETH. Each GPU gest x8 PCI-E lane and only using 1x PCI-E x16 lane.
Theorically using Zombie Mode, X99 board with PLCX chip(lots of PCI-E lanes) and Dual GPU, I can make a rig of 5 RadeonPro Duos and have a 10-gpu 4GB rig at near full ETH speeds.